chg: [GitHub action] install the python-cti-stix2 from the local submodule
chg: [GitHub action] install the python-cti-stix2 from the local submodule

SteveClement/MISP,SteveClement/MISP,MISP/MISP,MISP/MISP,MISP/MISP,MISP/MISP,SteveClement/MISP,SteveClement/MISP,MISP/MISP,SteveClement/MISP